Nigeria has a high burden of HIV-related brain disorders (NeuroAIDS), including mental health disorders and neurocognitive or neurological impairment. Over the last 4 years, the Multidisciplinary NeuroAIDS Research Training to Improve HIV Outcomes in Nigeria (D43TW009608-03) has developed three NeuroAIDS research cores with 10 investigators, two observational studies, and trained research support staff, including 3 psychometricians at the University of Ibadan (UI). Reviewing our progress with our Nigerian partners, we have identified residual gaps, which we propose to address by doubling the number of investigators and psychometricians through the Expanded Multidisciplinary NeuroAIDS Research Training to Improve HIV Outcomes in Nigeria. In the Mental Health Core, we will: 1) add implementation science by providing PhD training to a physician who excelled in the Northwestern University Master of Science in Clinical Investigation (MSCI) program, and 2) provide focused didactics and mentored research for 3 clinical psychologists/mental health nurses, thus expand UI's community of NeuroAIDS researchers to include these disciplines that are currently unrepresented but are key components of Nigeria's mental healthcare system. In the Translational and Clinical Sciences Core, we will provide intensive laboratory training for a pharmacology PhD candidate, postdoctoral training to a virologist, MSCI to a neurology/infectious diseases physician, and specialty clinical research training to a radiologist, all with integrated mentored research. In the Neuropsychological Infrastructure Core, we will provide postdoctoral neuropsychology fellowships for psychiatrists or neurologists to produce two experts who will train new psychometricians, as well as lead already-trained psychometricians and biostatisticians to create transformative capacity for neuropsychological assessment and analytics locally. Over half of each trainee's time will be in UI. The aggregated capacity of the cores will build into a research program equipped to lead in: 1) Mental Health Research- e.g., depression, stigma, disclosure, quality of life and, substance abuse; and 2) Translational and Clinical Research- e.g. understanding the biologic basis and optimal treatment of HAND; and unraveling the contribution of CNS compartmentalization, ART toxicity, drug resistance, cerebrovascular diseases, genomics, and co-infections to NeuroAIDS. The program will be distinguished by neuropsychological assessment expertise and locally standardized assessment instruments with appropriate norms to provide reliable and valid measurement of neurobehavioral consequences of HIV and its treatments in Nigeria. Training will be expanded further, knowledge disseminated, and ideas cross- fertilized through forums that we created in UI, including a monthly NeuroAIDS Collaboratory and a biannual NeuroAIDS Week with about 150 attendees/year. Manuscript writing and grantsmanship mentoring will prepare the trainees to become funded independent investigators. In 5 years, UI's multidisciplinary researchers will shoulder NeuroAIDS research in Nigeria with extramural funding, impacting the whole of Africa.